All About Engines

4° All About Engines cylinder is, therefore, greater than that of a large one. But this did not help him much, and he sought, by reading and experiment, for some means of preventing this. He found that steam required six times its weight of cold water to condense it without altering its temperature, thus rediscovering what his friend Professor Black had previously dis- covered. He made the cylinder of wood to reduce the cooling effect, he enlarged the area of the grate, and placed flues through the boiler to increase the rate of production of steam, but all to no purpose. Finally he concluded that the cylinder must, by some means or other, be kept as hot as possible, in order to avoid condensation. How to do this and at the same time to condense the steam was what puzzled him. One Sunday in the spring of 1765, when he was Fig. 16.— Watt’s model out for a walk, the solu- tion of the difficulty flashed across him. Why not have a separate condenser, a separate chamber into which the steam could pass for condensation, while the cylinder walls were kept as hot as they could be ? Rising early the next morning, he borrowed a syringe, about inches in bore and 10 inches long, made a cistern